succinic acid, a dicarboxylic acid of molecular formula C4H6O4 that is widely distributed in almost all plant and animal tissues and that plays a significant role in intermediary metabolism. It is a colourless crystalline solid, soluble in water, with a melting point of 185–187° C (365–369° F).
Succinic acid was first obtained as a distillation product of amber (Latin: succinum), for which it is named. The common method of synthesis of succinic acid is the catalytic hydrogenation of maleic acid or its anhydride, although other methods are being used and investigated. Succinic acid has uses in certain drug compounds, in agricultural and food production, and in manufacturing.